It is known in the prior art to raise shell fish of various kinds from a juvenile stage to maturity in habitats which are placed in the ocean. The purpose of the habitat is not only to contain the shell fish for eventual harvest at maturity but also to protect the shell fish from predators as they grow to maturity.
The habitats must be constructed in such a way that food can be conveniently introduced into the habitat for the shell fish contained therein. In addition, provisions must be made for the removal of waste products from the habitat in order to ensure the continued health of the growing shell fish. Finally, the habitat must provide relatively broad surfaces to which the shell fish can attach and on which they can move during their feeding and growth.
Some habitats of the prior art have been designed to rest on the ocean bottom and are therefore limited to use in relatively shallow offshore locations.
It has been proposed to avoid the limitation to shallow offshore locations by suspending habitats in the open ocean beneath surface floats. However, such an approach is impractical because the flotation system is exposed to the violence of storms at sea and the deleterious corrosive effects of the combination of air and water at the surface of the sea. In addition, habitats suspended from floats tend to move with the water currents resulting in a substantially stagnant condition of the water within the habitat due to the fact that there is little relative motion of the water with respect to the habitat.
U.S. Pat. No. 3,741,159, issued June 26, 1973 to Lazare Nathan Halaunbrenner discloses a submersible, positive buoyancy habitat. However, the habitat structure according to the teaching of this patent does not provide for an effective flushing action within the habitat. In addition, the structure of the habitat according to the teaching of Halaunbrenner presents substantial difficulty in connection with the feeding, hygiene and general maintenance of the shell fish to be raised therein.
It is the principal object of this invention to overcome the deficiencies of the prior art by providing an improved habitat structure, having substantially continuous self-flushing characteristics to help maintain hygienic conditions within the habitat, and which is more convenient to maintain, not only in terms of the structure itself but also in terms of placing, feeding, culling, grading and harvesting shell fish and the like in an open ocean environment with the habitat being relatively easy to manufacture and of relatively low cost.